Paul Allen's Living Computer Museum in Seattle had a wide range of vintage computers. Since his death, the museum has been closed. Last I checked, the fate of the collection is up in the air. They had a number of working older machines and had a staff capable of working on restoring them and keeping them running. It would be wonderful to get it reanimated. Best contact I have would be Aaron Alcorn at Vulcan (Paul Allen's venture firm).

Bruce Damer's Digibarn Computer Museum in Scotts Valley CA has been looking for someone to take over its collection since Bruce has redirected his personal research effort into AI from digital computer history.

Of course there is also the Computer History Museum in Mountain View, CA.

Wikipedia has a list of computer museums.

The Compuseum in Philadelphia is the latest new museum. (https://thecompuseum.org). It is the brainchild of James Scherrer who has done an amazing job collecting resources and support. Philadelphia is the original home of ENIAC (John Mauchly and J. Presper Eckert, Jr.).

And a word of caution. Real vintage machines are made from parts no longer manufactured, consume large amounts of power, are often water cooled, and need a large amount of physical space. They date from a time when the resource (compute cycles, storage) was so precious that having a staff of hardware engineers to keep the hardware working could be justified. On the software side, most systems were unique, non-standard, and supported by a team of five or more systems programmers. Economics forced a "small is beautiful" style on everything: those gifted programmers who could solve big problems with small speedy programs were in great demand.